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Threats to the Dusky Shark

The dusky shark gives birth only once every three years after reaching sexual maturation at the age of 20, meaning it has one of the lowest reproductive potentials among all sharks. A low reproductive rate makes the dusky shark especially vulnerable to exploitation by fishermen who pursued the shark for its meat, skin, liver, and fins for decades. In fact, the dusky shark is one of the most sought-after species in the shark fin trade. Dusky sharks continue to be threatened by commercial fishing that targets swordfish and tuna but that catch sharks as well (known as bycatch). Once hooked, most dusky sharks die before they can be released. As a result of these threats, the northwest Atlantic dusky shark population, which lives primarily in U.S. waters, has dropped to between 15 and 20 percent of its 1970 level (scientists know much less about the status of dusky shark populations in other parts of the world).

Endangered Species Act Listing

The dusky shark's highly depleted status in the northwest Atlantic requires strong action now. Despite a more than 10-year ban on U.S. recreational and commercial fisheries retaining dusky sharks, the region's population has failed to recover. The best chance dusky sharks have for recovery is to be listed under the Endangered Species Act, which would provide comprehensive protection for the species and its habitat. NRDC and WildEarth Guardians have both filed petitions to list the dusky shark under the Endangered Species Act.

Healthy fisheries and tourism industries rely on healthy coastal marine ecosystems, which the dusky shark plays an important role in maintaining. Shark ecotourism, which is expected to double in the next 20 years, already generates more than $314 million annually and employs an estimated 10,000 people worldwide. An ESA listing would also help protect critical dusky shark habitat in the United States, including coastal breeding and nursery areas and key feeding grounds.

An ESA listing for the region's dusky sharks would ensure that the federal government, with input from the fishing industry and other stakeholders, adopt the management measures necessary to stop the population's decline. Under the ESA, efforts to recover the dusky shark would be designed to reduce dusky shark fishing mortality with the minimum possible disruption to fishermen. For example, measures to curb bycatch, such as gear changes and targeted area closures, could protect dusky sharks while allowing fishermen to harvest target species. When the dusky shark population has recovered, the species can be delisted.

In response to petitions filed by NRDC and WildEarth Guardians, NMFS determined in May 2013 that
listing of the northwest Atlantic population of dusky shark may be warranted and initiated a formal status review. By law, the agency is required to make a listing decision within 12 months of the petition's submission date. NRDC's petition was submitted in February 2013, which means a listing decision is overdue.